There are known processes that permit the dyeing of fabrics only on one face with one dye or on both faces with dyes different from each other, by means of the pigment printing technique, that is, by using binding resins that fix the dye to the textile support.
One of these processes is described, for instance, in U.S. Pat. No. 3,775,046, which relates to the selective dyeing of cotton fabrics and polyester-cotton blends. Such processes, although imparting dyeings and printings which are, in general, sufficiently resistant to wet treatments, also confer on the fabric too stiff a hand.
Also known are processes that allow printing on both faces of a fabric by means of the transfer printing technique--a method which foresees the printing of a pattern onto an intermediate support, generally paper. Successively, the printed pattern is transferred onto the fabric by coupling together the support with the fabric itself and then subjecting the same to a heat treatment under pressure. The principle of this technique is described, for instance, in U.S. Pat. No. 3,874,846, concerning printing on both faces of synthetic fabrics, such as polyesters, polyamides, etc. Such processes are, however, very laborious because they require two successive printing operations, that is the printing of the intermediate support and that of the final support. Moreover, the light fastness and the sublimation of the prints from the final support are, in general, rather infrequent.